Energy dependence of electron transmission through a single glass capillary

The transmission of electrons through a single glass capillary with incident energies of 300, 500, 800 and 1000 eV was studied. The results reveal two distinctly different transmission characteristics depending on the tilt angle of the capillary with respect to the incident beam and the incident energy. For small tilt angles (< ∼ 2.5o) the rate of transmission fall-off with increasing angle is independent of energy within the experimental uncertainties, whereas for larger tilt angles (> ∼ 2.5o) the rate decreases with increasing energy. These observations suggest that fundamentally different phenomena govern the electron transmission in these two regions.